{"action":"Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260130144323-5bb5261c72fa or later.","affected":[{"fixed":"5.3.2-0.20260130144323-5bb5261c72fa","introduced":"0"},{"fixed":"10.11.11","introduced":"10.11.0-rc1"},{"fixed":"11.2.3","introduced":"11.2.0-rc1"},{"fixed":"11.3.1","introduced":"11.3.0-rc1"}],"component":"github.com/mattermost/mattermost-server","cve_ids":["CVE-2026-21386"],"ecosystem":"Go","epss":0.00191,"exploited":false,"fixed_versions":["5.3.2-0.20260130144323-5bb5261c72fa","10.11.11","11.2.3","11.3.1"],"ghsa_id":"GHSA-5mr9-crcg-8wh2","id":"tcs_01M5KEYJTV743WPGNR4WTEYFGJ","modified_at":"2026-03-23T18:56:15.398070Z","published_at":"2026-03-16T15:30:46Z","references":["https://osv.dev/vulnerability/GHSA-5mr9-crcg-8wh2","https://nvd.nist.gov/vuln/detail/CVE-2026-21386","https://github.com/mattermost/mattermost/commit/5bb5261c72faa476558a694c23581d24b734da41","https://github.com/mattermost/mattermost","https://mattermost.com/security-updates"],"severity":{"label":"medium","score":4.3},"sources":[{"source":"osv","source_id":"GHSA-5mr9-crcg-8wh2#Go/github.com/mattermost/mattermost-server","url":"https://osv.dev/vulnerability/GHSA-5mr9-crcg-8wh2"}],"summary":"Mattermost fails to use consistent error responses when handling the /mute command"}